Double-pin shackle



FIG. 1 is a perspective view of a double-pin shackle showing my new design;

FIG. 2 is a perspective view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines illustrate portions of the double-pin shackle that do not form a part of the claimed design. 

CLAIM The ornamental design for a double-pin shackle, as shown. 